Adherence to the Mediterranean Diet and depressive symptoms. A cross-sectional study among Italian university students: the UniFoodWaste study

Abstract Background: Depression is a major global health issue and is particularly prevalent among university students. Emerging evidence suggests that dietary patterns, especially the Mediterranean diet (MD), may influence mental health. This study aimed to examine the association between adherence to the MD and depressive symptoms among Italian university students. Study design: Cross-sectional study. Methods: A cross-sectional, web-based survey was conducted among students aged ≥18 y enrolled at the University of Milan (N = 2697). Adherence to the MD was assessed using the validated Medi-Lite score (range 0-18), while depressive symptoms were measured with the Patient Health Questionnaire-9 (PHQ-9), analyzed both as a continuous variable and using established cut-offs (≥5 and ≥10). Multivariable logistic and linear regression models were used to assess associations between MD adherence, individual dietary components, and depressive symptoms, adjusting for age and sex. Results: Higher MD adherence was significantly associated with fewer depressive symptoms. Each one-point increase in the Medi-Lite score was linked to lower odds of PHQ-9 ≥ 10 (aOR = 0.91, 95% confidence interval [CI]: 0.88-0.95; P = 0.001), PHQ-9 ≥ 5 (aOR = 0.89, 95% CI: 0.85-0.93; P < 0.001), and reduced PHQ-9 scores (β = -0.02, 95% CI: -0.03 to -0.01; P = 0.001). Consuming >2 portions/d of fruit (aOR = 0.60, 95% CI: 0.45-0.80; P = 0.001) and >2.5 portions/d of vegetables (aOR = 0.62, 95% CI: 0.45-0.85; P = 0.003) was associated with lower odds of depressive symptoms; vegetable intake also correlated with lower PHQ-9 scores (β = -0.14, 95% CI: -0.23 to -0.06; P = 0.001). Reduced meat intake (<1 portion/d) and regular olive oil use were further linked to lower depressive symptomatology. In contrast, alcohol consumption of 1 to 2 units/d (aOR = 1.41, 95% CI: 1.10-1.79; P = 0.006) and frequent use of food waste apps (≥1/wk: aOR = 4.26, 95% CI: 1.18-15.34; P = 0.027; β = 0.38, 95% CI: 0.00-0.76; P = 0.049) were associated with increased depressive symptoms. Conclusions: Greater adherence to the MD was associated with lower depressive symptoms among university students. Promoting MD adherence in student health programs may offer a useful non-pharmacological strategy to support mental well-being.